Faculty Opinions recommendation of In situ evolutionary rate measurements show ecological success of recently emerged bacterial hybrids.

2012 ◽  
Author(s):  
Elhanan Borenstein ◽  
Rogan Carr
Keyword(s):  
Evolutionary Rate ◽  
Ecological Success

scholarly journals Gut microbial compositions mirror caste-specific diets in a major lineage of eusocial insects

2018 ◽  
Author(s):  
Saria Otani ◽  
Mariya Zhukova ◽  
N’golo Abdoulaye Koné ◽  
Rafael Rodrigues da Costa ◽  
Aram Mikaelyan ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Plant Material ◽  
Amplicon Sequencing ◽  
Division Of Labour ◽  
Eusocial Insects ◽  
Major Lineage ◽  
Ecological Success ◽  
Microbial Symbionts ◽  
Royal Pair

AbstractEusocial insects owe their ecological success to the division of labour and processes within colonies often rely on the presence of specific microbial symbionts, but associations between microbial community compositions and castes with different tasks and diets within colonies remain largely unexplored. Fungus-growing termites evolved to use fungi to externally degrade plant material, complemented by specific and complex gut microbiotas. Here we explore to which extent division of labour and dietary differences within fungus-growing termite castes are linked to gut bacterial community structure. Using amplicon sequencing, we characterise community compositions in sterile (worker and soldier) and reproductive (queen and king) termites and combine this with gut enzyme, microscopy, andin situanalyses to further elucidate sterile caste-specific microbiota compositions. Gut bacterial communities are structured primarily according to termite caste and genus. In contrast to the observed rich and diverse sterile caste microbiotas, royal pair microbiotas are extremely skewed and dominated by few bacterial taxa, reflecting the specialised dietary intake and unique, reproduction-centred lifestyle of the queen and king.

Rendez vous with Saturn's rings

1984 ◽  
Vol 75 ◽  
pp. 743-759 ◽  
Author(s):  
Kerry T. Nock
Keyword(s):  
Solar Energy ◽  
Electric Propulsion ◽  
Power Source ◽  
Propulsion System ◽  
Low Thrust ◽  
Ring Plane ◽  
The Earth ◽  
Total Impulse ◽  
Saturn's Rings

ABSTRACTA mission to rendezvous with the rings of Saturn is studied with regard to science rationale and instrumentation and engineering feasibility and design. Future detailedin situexploration of the rings of Saturn will require spacecraft systems with enormous propulsive capability. NASA is currently studying the critical technologies for just such a system, called Nuclear Electric Propulsion (NEP). Electric propulsion is the only technology which can effectively provide the required total impulse for this demanding mission. Furthermore, the power source must be nuclear because the solar energy reaching Saturn is only 1% of that at the Earth. An important aspect of this mission is the ability of the low thrust propulsion system to continuously boost the spacecraft above the ring plane as it spirals in toward Saturn, thus enabling scientific measurements of ring particles from only a few kilometers.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Structural Studies on Mitotic Spindle Fibres

1978 ◽  
Vol 36 (3) ◽  
pp. 615-626
Author(s):  
J.R. Mcintosh
Keyword(s):  
Chemical Composition ◽  
Mitotic Spindle ◽  
Structural Studies ◽  
Mitotic Apparatus ◽  
Chemical Studies ◽  
Medical Interest ◽  
Spindle Fibres

The mitotic apparatus is a structure of obvious biological and medical interest, but it has proved to be a difficult cellular machine to understand. The chemical composition of the spindle is only slightly elucidated, largely because of the difficulties in preparing useful isolates of the structure. Chemical studies of the mitotic spindle have been reviewed elsewhere (Mcintosh, 1977), and will not be discussed further here. One would think that structural studies on the mitotic apparatus (MA) in situ would be straightforward, but even with this approach there is some disagreement in the results obtained with various methods and by different investigators. In this paper I will review briefly the approaches which have been used in structural studies of the MA, pointing out the strengths and problems of each approach. I will summarize the principal findings of the different methods, and identify what seem to be fruitful avenues for further work.

Sign in / Sign up

Export Citation Format

Share Document